Mounting device for boiler casings



Nov. 29, 1955 E, C, wlTZKE ,g1-AL 2,725,041

MOUNTING DEVICE FOR BOILER CASINGS Filed April 15, 1952 2 Sheets-Sheet l V INVENTORS Ernest C. Wzke l AT1-on Y FlorindoFCoZZA Nov. 29, 1955 E. c. wlTzKE: Erm. 2,725,041

MOUNTING DEVICE FOR BOILER CASINGS Filed April 15. 1952 2 Sheets-Sheet 2v INVENTORS Ernest C. Wfzke Florindo F.CozzA .rrToRl'z'-l vyv United States Patent 2,725,041 MOUNTING DEVICE FOR BOILERy CASIN GS Ernest C. Witzke, Bayside, N. Y., and vlorindo F. Cozza,

West Orange, N. J., assignors to Combustion Engineering, Inc., New York', N. Y., aA corporation of Delaware Application April 15, 1952, Serial No. 282,394

Claims. (Cl. 122-6) This inventionv relates to furnace'v wall structures and particularly to improved means for interconnectingI the exteriorcasings of furnace walls and'thefluid cooled tubes which line the interior of said walls.

This invention is an improvement over the organization ofU.- S. P-atent 2,223,215 issued November 26, 1940 tofW. l. Kun-z et al. which organization affords practical advantages ofa high order but whichunder certain conditions of commercial operation has, forreasons hereinafter explained, presented difficulties that the present invention. effectivelyv overcomes.

While the invention isherein described as used in the furnace wall of a steam generator, it is to be understood that it may equally well bev-used inv the walls of other furnaces.

Insteam generators of largecapacities the combustion rates' within the associated furnaces are exceedingly high, thereby:` developing extremelyA high temperatures lwithin said furnaces and. requiringv the vinterior faces .of the furnacefvvallsA to4 be vlined with steam generating: tubesar.- rangedy so that the boiler water circulates therethrough. During operation these furnace Wall tubes absorb heat fromy the fuel burning within the furnace and transmit thish heat to the boiler Water therewithin .causing a portion= thereof to be converted to steam.l TheV temperature ofthe furnace wall vtubes is substantially higher than the temperature of theA water circulating*therethrough, the latterbeing that of saturated steamat the prevailing pressurel under which the steam generator is. operating. Said walltubes are generally backed, outwardly ofthe furnace, by a refractory and by insulating material outside of said refractory. There is consequently a substantial temperatureA drop through the furnace wall since the temperature of:` theoutside surface ofthe insulation. is but slightly higher .than room temperature.

The wallstructure outside of the insulation usually'co. prises an outer-casing made up' of a gas tight. housing. of steel-1er. plastic sheets, which housing is supported and braced by vertical and horizontal stiifening-.f members. This outer` wall structureand the'inner wall tubes. are interconnectedY by means which maintain the desiredspacing; therebetween and which serve as a support for portionszof the wall. Because` of the difference in temperature between ythe inner wall tubes and the outer casing structure and-'consequently the difference ineexpansion therebetween, these spacing means must be\ capableof accommodating the resulting relative 'movements of the two' members.

It'isfanl object of this invention to provide improved meansfor spacing an outer furnace wall casing structure from the inner furnace Wall tubes, which means will adequately and freely accommodate relative .movement therebetween'resulting from the differences in. thermal expansion.

Other objects of the invention will appear and. be broughty out more fully in the following .description considered ,in connection with Vthe accompanyingdrawings, wherein:`

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Figure:l 1.-' is: ai horizontal. sectionsthrough atportionvof thex wall vof .a furnacey (with the lrefractory 'and'. insulation materials omit'tedsfrorn the right hand"y portion thereof) takemgenerally alongline' 1--1 in Figs. 2. and13v and-'showingftherfurnace wall tubeswith the casing structure spaced there-from by the :improved means of `:this invention;

Figure 2 is 4avsectionA takeny on line k2 2 tinvFig. lwith the refractory material removed;A

Figure' 3i is' a section. taken online 33 in'Figs. land 2;. and:

Figure14 -is a secti'onsimilar'toFig.. lofanoth'er form of thefinvention.l

Referring to the drawingszand yin particular to'Figs'. l, 2 and 3, fluid cooled tubesl. are shown.' as.v'ertically"dis posed'. along thev inner. face ofv affurnace wall.. generally designated'as'F.. Said tubesivare backed, outwardly'. of the furnace,- vby.l a .refractory material' .2` such'i as Itilwor'a plastic refractoryandl'by an insulatinglmaterialS-outside ofi said vrefractory material.. A sheet steelcasi'nfg: 4fof generallyV gas tightconstruction covers the outside'of the insulation .Ssandf is stiffen'ed by vertical memberslsuch as.bars;.5'.andi'horizcntallmembers suchas channels 6 securedy theretoysaidy b'arsrand channels being fastened together to form a'rigidsupport structure;r

Channel .shaped members or guides .7 are fastened 'to adjacent pairs -of thevvertieall'yl Idisposed vtubes '1f with'a flange ."8 ofsaid-lguide'fbeing welded longitudinallvof one tube 1in-each.'pair;v Web. 9 of saidwhann'el rnemberfor guide .'7 has-an'open endedslotfllO (Fig. 2) that extends parallel to flanges 8 and terminatessomewh'at inwardly off thel top.' edgef thereof. Positioned? interrnediateJ said flanges'. is a. plate-ori' sloef.` 11i arrangedtofreely' slide within .saidt guide-71m va; direction. 'parallel .to saidfia'nges `andzsaidrslot.- Saidshloe 11 hasal slot1'12 (Fig-2) extending transversely of I and generally' f spanning i saidl slot 10;` The:squared..portion'r13r of' bolt. 14 (Figi 2) tits within: slot 12 inzazmanner to permit free movement of said '.bolt` :lengthwise of vsaid .slot but: to `prevent :rotation of said'l bolttwthin said slot..v The'head'15of1bo1t`14 bearsagainst thefsid'e'of shoefll adjacent theftube 1`.'

Squared portionvl3'of'saidbolt is fof sufficient length tosextendl through the alignedslots 212 and 10vwhile` lallowinggsuicient..clearance, indicatedV as' 16; to permit free'movementof guide A7 relative lto shoe l1'1'andanfgl`e memberv 18.- Thei outerfendiof saidlbolt'14 is' of circularcro'ss section:- thereby "forming la shoulder at the junction; with said squaredy portion and' is provided withy threads for` there'ception-.of vnut 19.' Said threaded portion snug'- ly ts .within-a. suitable f hole inleg'` 17 of anglelf'member 18 so that upon. tightening; nut 19saidA leg isl clamped between. said lshoulder and said nut'thereby rigidly` holdnig.. bolt v14 tfin= itsA proper' position. `normal to the surface of leg 17. With this arrangement 'guide7 is free t'o move in. .both .the vertical'v and' lateral direction` within the limits permitted .by slot- 10- andslot. 12frespectively'.

Furnace ywall F isy provided withl a multiplicity of said angle` members 18' whicharey spaced vertically and arrangednormal to the axis of theltubes of said wall.y Each adjacent pair-of vvertically -disposed tubes 1, in theorganization-of Fig. 1,'.is heldflin spaced relation to` said angle members 18 by means. of theguide, shoe and'bolt arrangement hereinbefore described whereby the Aaxesof said tubes are maintained in substantial alignment.- Clip agles 20 are provided at spaced inter-vals along eachangle rnember-18 andy haveone flange fastened to angle mem bers 18 (Fig. 3) as. by.welding.with the other flange being. bolted to casing 4 by bolts 21.. Thus, angle member-.18 is. rigidly secured-to casing 4 and will accordingly movewithsaid casing..l

The. embodiment. of our.invention` disclosed in Fig..4 is. similar .to that of Figs. 1, 2v andv 3 ywith theexception that .in-. this.. embodiment vertically disposed tubes E15 are Iprovided with laterally projecting fins 24 and are therefore spaced apart a considerable distance for the accommodation of said lins necessitating a somewhat different arrangement for fastening the guide to the tubes. Since the spacing of the tubes is too great to economically secure a single guide to adjacent pairs of tubes each individual tube has a guide 8 welded thereto with each guide having a longitudinal slot similar to slot of guide 8 and being operatively associated with shoe 11, bolt 14, angle member 18, clip angle and casing 4 in the same manner as the organization of Figs. l, 2 and 3.

It will thus be seen that We have provided an arrangement for interconnecting the exterior casing of a furnace with uid cooled tubes lining the inside wall of the furnace which allows limited vertical and lateral movement of these elements relative to each other and which is extremely rugged in its construction.

In operation of a typical furnace where the walls are suspended from the furnace top (in well known conventional manner) both the casing 4 and the vertically disposed tubes 1 will increase in temperature and expand downwardly as a tiring of fuel in the furnace brings the furnace interior from cold or room temperature up to hot or operating temperature. The increase in the temperature of the tubes 1 will however be much greater than that of the casing 4 causing a downward expansion of the tubes which is considerably greater than the downward expansion of the wall and accordingly resulting in bolt 14 and shoe 11 (secured to casing 4) moving upwardly in slot 10 of guide 7 (secured to tubes 1) while any lateral movement of the tubes relative to casing 4 will be accommodated by horizontal movement of bolt 14 in slot 12 of said shoe 11.

Difficulty has been encountered in the case of prior art devices, typically illustrated by the aforementioned Kunz et al. Patent No. 2,223,215, because of binding of the shoe in the guide due to bending (under certain operating conditions) of the relatively long bolt used in such devices. The organization of our invention completely eliminates this source of difficulty by positioning the mounting for bolt 14 in juxtaposition to guide 7 and by securing the mounting for said bolt to casing 4 in such a manner (via clip angles 24)) as to also substantially eliminate the possibility of its bending. With this arrangement an extremely rugged structure is formed which has proved superior to any previously known means for. accomplishing the same purpose. The short bolts 14 overcome the difliculty heretofore encountered by the similar use of long bolts in furnace Walls; angle iron 18 furnishes a support for the insulating material 3 while serving to maintain definite alignment of the tubes 1 and rigidly supporting bolts 14 in a position normal to the tubes; and rigid fastening of angle members 18 and clips 2b maintains the parallel relation of casing 4 and flange 17 of angle 18 with the tubes 1 and therewith with the web 9 of guide 7,

While we have shown and described preferred cmbodiments of our new interconnecting means it is to be understood that such disclosure is merely illustrative and not restrictive and that variations and modifications may be made therein without departing from the spirit and scope of the invention. We therefore do not wish to be limited to the precise details set forth but desire to avail ourselves of such changes and alterations as fall within the purview of our invention.

What we claim is:

l. In a furnace wall having fluid cooled tube means arranged on the inner face and a casing on the outer face, spacing means between said tube means and said casing comprising members fastened to said tube means, each member having a slotted portion in a plane parallel to said wall and presenting an outer surface parallel to said wall, a shoe associated with the inner side of said last mentioned portion and being constructed and arranged to slide lengthwise of the slot therein but restrained from revolving about an axis normal to the plane of said wall, said shoe having a slot communicating with and extending transverse of the slot in said member, a bolt disposed with its head located on the inner side of said shoe and having a shank extending through both of said slots, said shank being of polygonal section at the head end and reduced to cylindrical section at the outer end thereby providing a shoulder at the junction of said two sections, said polygonal section fitting the slot in said shoe in a manner to prevent rotary motion but permit sliding movement relative thereto and being of slightly greater length than the depth of said two slots, a support member having an angled cross section with one leg thereof parallel to the plane of said wall and bored to receive the said outer end of a plurality of said bolts, a nut threadedly received on the outer end of said bolts for securing said one leg of said support member against said shoulder with the inwardly directed surface of the support member adjacent and parallel to the outer surface of said slotted member, and spaced support means rigidly securing said support member to said casing.

2. ln a wall structure including a pair of parallel heat exchange tubes, a channeled member having one longitudinal edge of its flange portions secured to each of said tubes parallel to the axis thereof and provided with an elongated slot in its web portion, said slot being parallel to the axis of said tubes and said web being parallel to the plane containing the axis of said tubes, a shoe slidably mounted in said channel in a manner to restrain rotary motion thereof, said shoe being formed with a slot communicating with and extending transversely of the slot in the web of said channel, a bolt disposed with its head located within said channel and having a shank extending through both of said slots, said shank-being of polygonal section at the head end and reduced to cylindrical section at the outer end thereby providing a shoulder at the junction of said two sections, said polygonal section fitting the slot in said shoe in a manner to prevent rotary motion but permit sliding movement relative thereto and being of slightly greater length than the depth of said two slots, a support member having an angled cross section with one leg thereof parallel to the plane of the axis of said tubes and bored to receive said outer end of said bolt, a nut threadedly received on the outer end of said bolt for securing said one leg of said support member against said shoulder, a casing substantially parallel with said tubes and adjacent said support member, and spaced support means rigidly securing said support member to said casing.

3. A Wall structure as defined by claim 2 wherein the means for securing the casing to the support member comprise a plurality of spaced members of angled cross section having one leg parallel with and welded to the other leg of said support member and the other leg parallel with and bolted to said casing.

4. In a wall structure including a heat exchange tube, a channeled member having the longitudinal edges of its ilange portions secured to said tube parallel to the axis thereof and provided with an elongated slot in its web portion said slot being parallel to the axis of said tube, a shoe slidably mounted in said channel in a manner to restrain rotary motion thereof, said shoe being formed with a slot communicating with and extending transversely of the slot in the web of said channel, a bolt disposed with its head located within said channel and having a shank extending through both of said slots, said shank being of polygonal section at the head end and reduced to cylindrical section at the outer end thereby providing a shoulder at the junction of said two sections, said polygonal section fitting the slot in said shoe in a manner to prevent rotary motion but permit sliding movement relative thereto and being of slightly greater length than the depth of said two slots, a support member having an angled cross section with one leg thereof extending transversely of the axis of said tube and lying parallel to the surface of said web portion, said leg being bored to receive said outer end of said bolt, a nut threadedly received on the outer end of said bolt for securing said one leg of said support member against said shoulder, a casing adjacent the other leg of said support member, and means rigidly securing said casing to said support member.

5. A wall structure as defined by claim 4 wherein the means for securing the casing to the support member comprise a plurality of spaced members of angled cross section having one leg parallel with and welded to the other leg of said support member and the other leg parallel with and bolted to said casing.

References Cited in the le of this patent UNITED STATES PATENTS 

